chore: delete dead AuthenticationStorage - WPB-10448

[johnxnguyen]

WPB-10448 [iOS] Renew access token if needed

Issue

This PR is a follow up to #2084 in which I forgot to delete the AuthenticationStorage protocol and use the new AuthenticationManager in the PushChannelService. This PR fixes that, and also sets up an Assembly object to lazily initialize these services.

---

Checklist

• Title contains a reference JIRA issue number like [WPB-XXX].
• Description is filled and free of optional paragraphs.
• Adds/updates automated tests.

---

UI accessibility checklist

If your PR includes UI changes, please utilize this checklist:

• Make sure you use the API for UI elements that support large fonts.
• All colors are taken from WireDesign.ColorTheme or constructed using WireDesign.BaseColorPalette.
• New UI elements have Accessibility strings for VoiceOver.

[github-actions]

Test Results

195 tests   195 ✅  2s ⏱️
 27 suites    0 💤
  2 files      0 ❌

Results for commit f80b914.

♻️ This comment has been updated with latest results.